Efficient, selective herbicides. It is mainly used for post-emergence weed control in bean fields and has special effects on the control of broad-leaved weeds. Its principle of action is to absorb through leaves and destroy photosynthesis. The agent is also very active in the soil. Soybean seedlings 1 to 3 compound leaves, weeds 2 to 5 leaf stage, with 25% liquid agent 9 ~ 20mL/100m2, spraying weed stems and leaves with water. At this dose, pre-emergence application is superior to pre-sowing application. The disadvantage is that there will be certain phytotoxicity to soybeans, but it will recover quickly. Application of pre-emergence application after sowing will not produce phytotoxicity to soybeans. 2. Selective herbicides. Absorption of the photosynthesis of the plant can be achieved through leaf absorption. It has special effects on control of broad-leaved weeds and is very active in soil.